• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.428-434
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• 2001

A viscous substance producer strain BS62, which was isolated from conventional Chungkookjang, was examined for its productivity of levansucrase and levan during soybean fermentation at $37{\circ}C$. After one day of cultivation, the enzyme activity reached the highest level, 8 units $ml^{-1}$. Extracts of fermented soybeans were precipitated by ethanol and hydrolyzed by either 0.1 N HCl or invertase, and the hydrolyzates were analyzed using thin layer and ion chromatographies. Fructose was the only sugar detected. This suggest that fructose was derived from the levan produced by the strain BS62 during soybean fermentation. The aerobic, endospore-forming bacterium BS62 was identified as a Bacillus subtilis sp., based on the composition of its cellular fatty acids and phylogeny, which was determined by its 16S rDNA sequence.

• Animal Systematics, Evolution and Diversity
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• v.16 no.2
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• pp.203-211
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• 2000

Partial mitochondrial 16S rDNA and COI gene were amplified using PCR and sequenced for four species of oysters in Korea. Phylogenetic relationships among them were inferred from their aligned sequences by neighbor-joining method. The sequence comparison data of two mitochondrial genes showed that the genetic distinction between two oyster genera (Crassostreo and Ostrea) was obvious. Phylogenetic analysis based on the nucleotide sequences and A+T percentage of two genes indicates that C. gigas and C. nippona strongly formed a sister group and then C. ariakensis was clustered with the clade although that based on amino acid sequences of COI gene by neighbor-joining method represented different phylogenetic tree.

• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.985-992
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• 2007

The diversity of archaeal strains from six hypersaline environments in Turkey was analyzed by comparing their phenotypic characteristics and 16S rDNA sequences. Thirty-three isolates were characterized in terms of their phenotypic properties including morphological and biochemical characteristics, susceptibility to different antibiotics, and total lipid and plasmid contents, and finally compared by 16S rDNA gene sequences. The results showed that all isolates belong to the family Halobacteriaceae. Phylogenetic analyses using approximately 1,388 bp comparisions of 16S rDNA sequences demonstrated that all isolates clustered closely to species belonging to 9 genera, namely Halorubrum (8 isolates), Natrinema (5 isolates), Haloarcula (4 isolates), Natronococcus (4 isolates), Natrialba (4 isolates), Haloferax (3 isolates), Haloterrigena (3 isolates), Halalkalicoccus (1 isolate), and Halomicrobium (1 isolate). The results revealed a high diversity among the isolated halophilic strains and indicated that some of these strains constitute new taxa of extremely halophilic archaea.

• Animal cells and systems
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• v.6 no.2
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• pp.145-151
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• 2002

Phylogenetic signal present in the mitochondrial 16S ribosomal RNA gene (16S rDNA) and the nuclear large subunit ribosomal RNA gene (28S rDNA) was explored to assess their utility in resolving family level relationships of the superfamily Tephritoidea. These two genes were chosen because they appear to evolve at different rates, and might contribute to resolve both shallow and deeper phylogenetic branches within a highly diversified group. For the 16S rDNA data set, the number of aligned sites was 1,258 bp, but 1,204 bp were used for analysis after excluding sites of ambiguous alignment. Among these 1,204 sites, 662 sites were variable and 450 sites were informative for parsimony analysis. For the 28S rDNA data set, the number of aligned sites was 1,102 bp, but 1,000 bp were used for analysis after excluding sites of ambiguous alignment. Among these 1000 sites, 235 sites were variable and 95 sites were informative for parsimony analysis. Our analyses suggest that: (1) while 16S rDNA is useful for resolving more recent phylogenetic divergences, 28S rDNA can be used to define much deeper phylogenetic branches; (2) the combined analysis of the 16S and 28S rDNAs enhances the overall resolution without losing phylogenetic signal from either single gene analysis; and (3) additional genes that evolve at intermediate rates between the 16S and 28S rDNAs are needed to further resolve relationships among the tephritoid families.

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.296-302
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• 2010

Microcystis (Cyanobacteria, Chroococcales) is one of the green tide-causing organisms in freshwaters, and some species produce microcystin that is hepatotoxin. In the aspects of freshwater quality controls and health concerns, therefore it is necessary to manage the harmful organisms. In the present study, RNA polymerase beta subunit (rpoB) gene sequences of Microcystis were determined and characterized in order to use a potential marker for the molecular detections of the species. Microcystis rpoB showed high divergences of DNA similarity and genetic distances when compared with those of 16S rRNA, and the molecular differences were statistically significant (Student t-test, p<0.05). Parsimony analyses showed the rpoB gene evolves more than 2-fold faster than 16S rRNA. In addition, phylogeny of the rpoB gene separated each M. aeruginosa strain more clearly compared with a 16S rRNA tree. This study found that the order Chroococcales, including Microcystis, has approximately two rRNA operons and single copy of the rpoB gene in their chromosomes. These results suggest that the rpoB gene is a useful marker for the molecular phylogenetics and the detection of Microcystis.

• Journal of Microbiology
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• v.44 no.5
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• pp.566-571
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• 2006

An archaeal 16S rRNA gene library was constructed from mangrove soil. Phylogenetic analysis revealed archaea in mangrove soil including the Crenarchaeota (80.4%) and Euryarchaeota (19.6%) phyla. The archaeal community in mangrove soil appears to be a mixture of organisms found in a variety of environments with the majority being of marine origin.

• Journal of Microbiology and Biotechnology
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• v.14 no.1
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• pp.205-211
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• 2004

A 16S rDNA clone library was generated to investigate the bacterial diversity in tidal flat sediment in Ganghwa Island, Republic of Korea. A total of 103 clones were sequenced and analyzed by comprehensive phylogenetic analyses. No clones were identical to any of known 16S rRNA sequences in public databases. Sequenced clones fell into thirteen lineages of the domain Bacteria: the alpha, beta, gamma, delta, and epsilon Proteobacteria, Actinobacteria, CFB group, Chloroflexi, Acidobacteria, Planctomycetes, Verrucomicrobia, and known uncultured candidate divisions (OP11, BRC1, KSB1, and WS1). Two clones were not associated with any known bacterial divisions. The majority of clones belonged to the gamma and delta Proteobacteria (46.7%). Clones of Actinobacteria were distantly related to known taxa. It is evident from 16S rDNA-based community analysis that the bacterial community in tidal flat sediment is remarkably diverse and unique among other marine environments examined so far.

• The Plant Pathology Journal
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• v.18 no.3
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• pp.109-114
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• 2002

To evaluate the phylogenetic and taxonomic status of the phytoplasmas associated with water dropwort (Oenanthe javanica DC) disease in Korea and Japan, their 16S rDNA was analyzed. DNAs extracted from water dropworts collected in Korea (Kyongnam province) and Japan (Chiba prefecture) affected by witches' broom and yellows were subjected to PCR using phytoplasma-specific primers, which amplified a 1.4-kbp fragment that included the 16S rDNA. Phytoplasmas were characterized by RFLP analysis using AluI, HaeIII, HhaI, KpnI, MseI, and RsaI restriction enzymes and by sequence analysis of the PCR products. The mater dropwort witches'broom (WDWB) and water dropwort yellows (WDY) 16S rDNA sequences were identical and closely related to onion yellows (OY, 99.9% identity), which belong to the aster yellows (AY) 16S-subgroup. However, the KpnI RFLP analyses clearly distinguished the WDY and WDWB phytoplasmas from the OY phytoplasma. The phylogenetic analysis based on 16S rDNA showed that WDWE and WDY phytoplasmas are members of a relatively homogeneous group that evolved from a common ancestor.

• Korean Journal of Microbiology
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• v.47 no.3
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• pp.268-274
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• 2011

Anabaena (Cyanobacteria, Nostocales) are important for water quality controls, because they are often responsible for freshwater green tides; moreover, some species are reported to produce hepatotoxin. In this study, we sequenced RNA polymerase beta subunit (rpoB) gene of Anabaena, and evaluated their sequences for the potential use of a molecular taxonomic marker in this taxon. Anabaena rpoB showed low DNA similarity and high genetic divergences when compared those of 16S rRNA, and the molecular differences were statistically significant (Student t-test, p<0.01). Parsimony analyses showed the rpoB gene evolves 4.8-fold faster than 16S rRNA. In addition, phylogeny of the rpoB gene separated each Anabaena strain more clearly compared with a 16S rRNA tree. These results suggest that the rpoB gene is a useful marker for the molecular phylogenetics and the species discrimination of Anabaena.

• Molecules and Cells
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• v.22 no.1
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• pp.78-88
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• 2006

The phylogeny of the subfamily Tephritinae (Diptera: Tephritidae) was reconstructed from mitochondrial 16S ribosomal RNA gene sequences using 53 species representing 11 currently recognized tribes of the Tephritinae and 10 outgroup species. The minimum evolution and Bayesian trees suggested the following phylogenetic relationships: (1) monophyly of the Tephritinae was strongly supported; (2) a sister group relationship between the Tephritinae and Plioreocepta was supported by the Bayesian tree; (3) the tribes Tephrellini, Myopitini, and Terelliini (excluding Neaspilota) were supported as monophyletic groups; (4) the non-monophyletic nature of the tribes Dithrycini, Eutretini, Noeetini, Tephritini, Cecidocharini, and Xyphosiini; and (5) recognition of 10 putative tribal groups, most of which were supported strongly by the statistical tests of the interior branches. Our results, therefore, convincingly suggest that an extensive rearrangement of the tribal classification of the Tephritinae is necessary. Since our sampling of taxa heavily relied on the current accepted classification, some lineages identified by the present study were severely under-sampled and other possible major lineages of the Tephritinae were probably not even represented in our dataset. We believe that our results provide baseline information for a more rigorous sampling of additional taxa representing all possible major lineages of the subfamily, which is essential for a comprehensive revision of the tephritine tribal classification.